LU-9120 lnet: set health sensitivity from lnetctl

LU-9120 lnet: set health sensitivity from lnetctl

Added an lnetctl command to set the health sensitivity
from userspace.

lnetctl set health_sensitivity {>0}

0 - turn off health evaluation
>0 - sensitivity value not more than 1000

Test-Parameters: forbuildonly
Signed-off-by: Amir Shehata <ashehata@whamcloud.com>
Change-Id: Ic9289b06c5c9285a69c1819a33b79e954319a01e
Reviewed-on: https://review.whamcloud.com/32779
Reviewed-by: Sonia Sharma <sharmaso@whamcloud.com>
Reviewed-by: Olaf Weber <olaf.weber@hpe.com>
Tested-by: Jenkins